Order Hymenomycetes. Tribe TremeUini} 



Plate XLII. 



EXIDIA GLANDULOSA, ^«&^. 



Witches Butter. 



Gen. Cliar. Receptacle margined, gelatinous, tremulous, distended, homogeneous, covered above only with the 

 hymeniuin. Sporidia at length bui-sting forth elastically. Named from exudo, to exude? 



Spec. CJiar. ExiDiA glandulosa. Effused, more or less plane, thick, undulated ; the hymenium beset with 

 conical papillate spicules ; varying in colour from whitish to brown, and deep cinereous, at length black ; generally 

 somewhat turbinate ; slightly plicate and gyrose below, much wrinkled and lacunose above ; substance tender, thin, 

 gelatinous, smooth above, beneath rough like crape. The entire plant collapsing when dry, so as to be with 

 difficulty recognised ; re-assuming its pristine form with the application of moisture, and giving out a bright 

 brown tinge to water. 

 ExiDi,\ glandulosa. Fries, Berkeley. 

 Tremella glandulosa, BuUiard, Oreville, Witheriu(j. 

 spiculosa, Persoon. 



Hah. On trunks and ftillen branches, particularly of ash. Autumn and winter. 



If at a cursory glance the present subject from its hue and style of growth should be confounded with 

 Bulgaria inquinans, very little attention is needed to ascertain that in botanical characteristics they differ 

 essentially. The Bulgaria is a top-shaped cup, at fkst closed, fdled witli a gelatinous substance, in which 

 the reproductive bodies are immersed; Exidia (/Imuhdosais not cup-shaped, but nearly plane, as to its 

 entire configuration, that upper plane siu-face being smooth and shining, but wrinkled into a mesli-like 

 series of shallow cells or depressions, sometliing hke a Morel ; and upon this surface oidy the hymenium is 

 situated. The inferior sterile side is sub-tomentose, " rough like black crape " describes it exactly : being 

 of a very flaccid consistence when moist, the margins often hang over so as to conceal the under surface 

 entirely till Hfted up ; and this reversed position it retains in drying ; then care is required to discriminate 

 it from Tremella Jlmhriata, a rare plant, but in colour, form, and general appearance strongly resembling it. 

 Tremella Jhnhriata is gelatinous and tremulous when moist, brittle and crisp when dry, so is our Ex'ulia ; 

 the Trem,ella is black, plaited and corrugated, gathered beneath into a central point, which is inserted 



' Eeceptacle various in form, of a more or less gelatinous substance. Sporidia free, at length bursting forth. 



2 The name Ex'uUa gives a wrong impression, that of a liquid substance oozing out ; this is not the case. 

 Exidiaa grow out, as Tremellas do, from beneath the bark, taking their origin among the fibres of the inner stratum ; 

 but in the very first stage of developement, they are membranaceous rudiments of tlie future plant and not mere 

 gelatine exuded. 



